L3: Bones, ligaments and joints of the forearm (incl. elbow)

Question 1

humerus

Answer 1

long bone of arm
articulates with scapula proximally - GH joint
articulates with bones of the forearm distally - ulna medially + radius laterally

Question 2

wrist drop

Answer 2

because wrist extensors stop working without input from the radial nerve

Question 3

ulnar nerve

Answer 3

runs postero-inferior to the medial epicondyle

hitting your funny bone is in fact a compressive injury to the ulnar nerve

Question 4

golfers elbow

Answer 4

medial epicondyle: proximal attachment for muscles that flex the wrist. used to flex wrist in a golf swing

Question 5

tennis elbow

Answer 5

lateral epicondyle: proximal attachment for muscles that extend the wrist. used in backhand strokes in tennis

Question 6

ulna and radius

Answer 6

bones of forearm
anatomical position: ulna medial + radius lateral

articulate with the humerus proximally - elbow joint

articulate with the carpals distally - wrist

Question 7

ulna - proximal features

Answer 7

large trochlear notch
large olecranon process
coronoid process
radial notch
ulnar tuberosity

Question 8

ulna - shaft

Answer 8

interosseous ridge descends along the lateral shaft

Question 9

ulna - distal features

Answer 9

head of ulna
styloid process

Question 10

radius - proximal features

Answer 10

head of radius
neck
radial tuberosity

Question 11

radius - shaft

Answer 11

interosseous ridge

Question 12

radius - distal features

Answer 12

tubercles and groves on posterior surface
styloid process ( larger than ulna)

Question 13

radius role

Answer 13

moves around the ulna during supination and pronation of forearm

Question 14

interosseous membrane

Answer 14

aka interosseous ligament
fibrous joint [syndesmosis]
sheath of fibrous connective tissue
between interosseous ridges of ulna and radius
prevents separation, yet allows for pronation and supination of forearm

Question 15

movements of the elbow

Answer 15

extension
flexion

Question 16

movements of the forearm

Answer 16

supination/ pronation

these movements occur at the:
proximal radioulnar join
distal radioulnar joint

Question 17

elbow joint - fibrous capsule

Answer 17

classified as synovial hinge joint
-joint capsule lined by synovium
-synovial fluid inside the capsule
-articular surfaces of bones lined by hyaline cartilage
capsule attached to the articular margins of joint

Question 18

elbow joint

Answer 18

is loose anteriorly / posteriorly to allow for a full range of flexion / extension

in hyperextension injuries, the anterior joint capsule can be stretched / ruptured

Question 19

elbow joint - ulnar collateral ligaments

Answer 19

reinforces the joint medially

superior band
inferior band
posterior band

Question 20

elbow joint - radial collateral ligament

Answer 20

reinforces the joint laterally
base is attached to the annular ligament and ulna
apex attaches to the lateral epicondyle

Question 21

elbow dislocation

Answer 21

very stable hinge synovial joint
mechanism of injury
posterior dislocation
- usually FOOSH
anterior dislocation
- rare
- high energy incidents

Question 22

radioulnar joints - 3

Answer 22

proximal radioulnar joint
intermediate radioulnar joint
distal radioulnar joint

Question 23

proximal radioulnar joint

Answer 23

radial head in radial notch of ulna
synovial pivot joint
in same capsule as elbow joint

Question 24

intermediate radioulnar joint

Answer 24

fibrous joint: syndesmosis
formed by interosseous membrane

Question 25

distal radioulnar joint

Answer 25

ulnar head in ulnar notch of radius
synovial pivot joint

Question 26

the annular ligament

Answer 26

position:
anterior margin of radial notch of ulna
around neck of radius
to posterior margin of radial notch of ulna

holds the radial head in the radial notch of the ulna

Question 27

nursemaid’s elbow

Answer 27

the head of the radius tends to be proportionately smaller in children under 5 years
if enough force is applied in the distal direction, it can slip under the annular ligament and become dislocated